Known processes for purifying monoclonal antibodies and other biological materials are often required to remove unwanted impurities, which is particularly important when the biologic is produced for therapeutic uses. One way to remove impurities is through diafiltration. Diafiltration is known in the art and described in, for example, Wayne P. Olson, Separations Technology: Pharmaceutical and Biotechnology Applications (Interpharm Press 1995); Munir Cheryan, Ultrafiltration and Microfiltration Handbook (2d ed. CRC Press 1998); Stefan Behme, Manufacturing of Pharmaceutical Proteins (Wiley-VCH 2009); and Glyn N. Stacey, Medicines from Animal Cell Culture (John Wiley 2007), all of which are incorporated herein by reference in their entireties.
Ch14.18 (also referred to herein as “dinutuximab”) is an anti-GD2 monoclonal antibody and has been described in Gillies et al., Journal of Immunological Methods 125:191-202 (1989), which is incorporated herein by reference in its entirety. When using the ch14.18 antibody for therapeutic purposes, it is important to remove impurities such as bis(2-hydroxyethyl)amino-tris(hydroxymethyl)methane (Bis-tris) to ensure the safety and effectiveness of the monoclonal antibody. Thus, there is a need for methods of removing unwanted impurities from biologic compositions.